Glass that is fairly clear in color and highly transmissive to visible light (e.g., at least 75% transmissive, or even more preferably at least 80% transmissive) is sometimes desirable. One way of achieving such as glass is to use very pure base glass materials (e.g., substantially free of colorants such as iron). However, base materials with a high degree of purity are expensive and thus not always desirable and/or convenient. In other words, for example, the removal of iron from glass raw materials has certain practical and/or economical limits.
First and second standard high transmission glass compositions are as follows. These standard compositions, and the methods of making the same, will be referred to herein as Comparative Example (CE) 1 and Comparative Example (CE) 2. The amounts of the various materials below for CE 1 and CE 2 are listed in terms of weight percentage (%) in the glass, unless otherwise indicated, and the optical characteristics were measured at a reference thickness of about 6 mm. Visible transmission was measured in terms of Lta (Ill. C. 2 deg.), whereas the a* and b* transmissive color values were measured in accordance with Ill. D65, 10 deg.